In high speed signaling, a single-ended signal is typically transferred on a single signal line by using a fixed reference voltage as a reference, such as a VREF voltage, that has an approximate fixed level or value at devices transferring and receiving the varying single-ended signal. However, a reference voltage generally does not track variations that may occur when providing signals, to a device, such as an integrated circuit memory device. For example, voltage sources may be noisy or provide a voltage level that is non-ideal and thus provide a reference voltage that is non-ideal. Termination values in a channel or device may change under various configurations or environmental conditions. Also, a reference voltage should take into account the overall channel effect, such as the length of the channel, when transferring signals.
Furthermore, as signal transfer rates increase in frequency and signal voltage swings are decreased, an erroneous bit value may be obtained when sampling voltage values because a reference voltage value is not adjusted to take into account the resulting smaller voltage difference between a high voltage value (or high logic value) and the non-ideal low voltage value (or low logic value).
If these variations and increases in signal frequencies are not taken into account, a non-ideal reference voltage may result in the reduction of system operating performance.